1. Field
One embodiment of the invention relates to a head used in a disk device such as a magnetic disk device, a head suspension assembly provided with the head, and a disk device provided with the head suspension assembly.
2. Description of the Related Art
A disk device, e.g., a magnetic disk device, comprises a magnetic disk in a case, a spindle motor that supports and rotates the disk, a magnetic head that writes and reads information to and from the disk, and a carriage assembly that supports the head for movement with respect to the disk. The carriage assembly comprises a rockably supported arm and a suspension extending from the arm. The magnetic head is supported on an extended end of the suspension. It has a slider mounted on the suspension and a head portion on the slider. The head portion includes a reproducing element for reading and a recording element for writing.
The slider has a facing surface that faces a recording surface of the magnetic disk. The facing surface of the slider is formed having a negative-pressure chamber as a negative-pressure generating section for generating a negative pressure. The suspension applies to the slider a given head load that is directed toward a magnetic recording layer of the magnetic disk. As the magnetic disk device is operated, an air current is produced between the rotating magnetic disk and the slider. Thereupon, the facing surface of the slider is subjected to a positive pressure that is opposite to the negative pressure generated by the negative-pressure chamber, that is, a force to fly the slider above the recording surface of the disk. The slider is flown with a fixed gap kept above the disk recording surface by balancing the flying force and the head load.
The flying height of the slider is expected to be substantially the same in any radial position on the magnetic disk. The rotational frequency of the magnetic disk is constant, while its peripheral speed varies depending on the radial position. Since the magnetic head is positioned by the rotary carriage assembly, moreover, the yaw angle (angle between the direction (track direction) of the current and the center line of the slider) also varies depending on the radial position on the disk. In designing the slider, therefore, change of the flying height attributable to the radial position on the disk must be restrained by suitably utilizing the aforesaid two parameters that vary depending on the radial position.
With the recent improvement in the recording density, miniaturization of sliders has been promoted, and so-called pico-sliders, femto-sliders, etc. have been investigated. If a slider is miniaturized so that its transverse dimension is reduced, the roll or swing of the slider around its longitudinal axis is caused easily. The roll angle of the slider changes depending on the radial position on the disk. If the roll angle of the slider varies, the recording/reproducing characteristics fluctuate.
In order to prevent the variation of the roll angle, a novel magnetic head slider is proposed in Jpn. Pat. Appln. KOKAI Publication No. 9-330510, for example. In this head slider, a negative-pressure generating section of a slider is divided into a plurality of parts to disperse the inclination of a negative-pressure distribution, so that the slider can be restrained from rolling even if the yaw angle is increased.
If the negative-pressure generating section is thus divided for dispersion, however, the flexibility of its design lowers and its area is reduced, so that there is a possibility of the resulting negative pressure lowering. In this case, it is hard to maintain a stable flying posture of the slider, so that the reliability of the recording/reproducing characteristics may possibly be spoiled.